Engine starter clutch



Aug. 3l, 1948. c. A. BALTON ENGINE STARTER CLUTCH Original Filed March 25, 19434 Jiu/erzhl? mw n Patented Aug.` 31, 1948 UNITED STATES" PATENT OFFICE Original application March .23,v 1943. Serial No. 480,173. Divided and this application October 30, 1944, Serial No. 561,017

13 Claims. l

This invention relates to a clutch and more particularly to a jaw clutch adapted to kbe used in conjunction with an* airplane starting motor as shown in my cooending application Serial No. 480,173, led March 23, 1943, for Internal combustion engine of which this is a divisional application. Y

One of the objects of the invention is to provide a reliable, lightweight, `high power and high speed clutch which can be used to couple the starting motor for an airplane engine 'with the -airplane engine itself.

Another object is to provide such a clutch which is very compact and also is self-contained.

Another object is to provide such a clutch which will stand up under conditions of severe and constant use.

Another object is to provide such a clutch which is positive when closed and completely disengaged when open and which, when closed, will transmit heavy torque forces.

Another object is to provide a jaw clutch including a yielding drive to avoid breakage in they .the present invention in elevation.

Fig. 2 is a View similar to Fig. l'shofwing parts of the clutch and end head of the internal combustion engine broken away. f

Fig. 3 is an enlarged vertical central section f through therclutchshown in Figs. 1 and 2 and showing .parts in elevation.

Fig. 4 is a fragmentary section, taken on line The clutch or coupling is shown asmounted on the starting-motor for a much larger airplane motor, the construction of these motors being illustrated in detail in my said copending application LSerial No. 480,173, iiled March 23, 1943, for Internal combustion engine of which this application is a division.Y Thestarting motor is shown as having an end head I forming the casing for the gearing driven by the starting motor,v this gearing being represented .by the driven gear I I. This end head or gear case I0 is shown as being open at its extremity, this opening-being surrounded by a rim I2 to which the clutch or coupling forming the subject of the present invention relates.

this invention is shown as driven'through plan- (Cl. 12S-179) etary gearing from the pinion II and for this purpose the pinion II is shown as meshing with a gear I5, the hubof this gear I5 being formed to provide a pinion I5 and rotatably mounted on a bearing bushing I8 mounted on the hub I9 of a spider 20. This spider carries a plurality of pinions 2l, these pnions being preferably three in number and each mounted on a roller bearing 22 carried by a pin 23 formed integrally with the spider 2i).v Each of the pinions 2l meshes with a stationary ring gear 25 which is rshown as secured, byl screwsv 26, to the rim l2 of the end head I0. These screws 2S also serve to hold the rim 28 of a cylindrical casing Z9 againstthe outer face of the ring gear 25. As best shown in Figs. 2 and 3, the spider 20 is formedto provide a cylindrical extension 30 which is journaled in the stationary cylindrical casing 23 by means of.

roller bearings 3 I y As best shown in Fig. 3, this spider is also formed to provide a clylindrical centering stem 32 projecting coaxially into the chamber formed by the cylindrical extension 30 and centering a This cylindrical support is formed to provide a coaxial hub 35 of reduced diameter and is provided With an axially extending iiange or rim 36 which forms, with the hub 35, a cylindrical groove 38. In this groove is varf-- ranged the sleeve 40 of a jaW clutch 4I, this jaw;l clutch having face teeth or jaws 42 at its end.`

The jaw clutch 4I and its cylindrical support y34 are compelled to rotate in unison through four pins 42 in the cylindrical support 34 and extending into slots 43 in the sides of the sleeve 40 of the jawl clutch. As will be noted from Fig. 4, each of the slots 43 is disposed at an angle to the axis of the clutch so that as the clutchl is moved axially in and out it is turned to a degree i determined by the angularity of the slots 43.

This axial movement of the clutch 4I can' be effected manually, the jaw clutch being normally heldin its extended or dotted line position las sho'wn in Fig. 3 by a helical compression spring 45 which is arranged in a recess provided in the end of the cylindrical support 34 for the' clutch and urges the clutch 4| outwardly; The jawA clutch 4I is retracted inwardly by means of a' manually operated rod 44 which extends axially through the cylindrical support 34 for the clutch jaw and the spider 20. As best shown Iin Figs.l f

2 and 3, the free end of this rod 44 is arranged in the Xchamber forme-d by the end head or gear case I0 of the engine :and can be moved to the.

left Vby any suitable :form of manual control (not shown), anA example 'ofi which is shown in `my' said parent application.

'The drive between the spider 29 and the cylindrical support 34 for the jaw clutch 4l includes a friction clutch which provides a yielding drive between these two members so as to avoid. breakage in the event of lan overload being placed upon the starting motor. For this purpose a series of clutch plates 43 are provided in the space between the cylindrical extension 3S of the spider 2li and the cylindrical support 34 for the jaw clutch 4| Alternate plates of this group are keyed to the cylindrical extension Sii o-f the spider 20 so as to rotate therewith and the intermediate plates 48 are similarly keyed to the cylindrical support 54 for the jaw clutch di. The drive is therefore determined by the frictional engage-- ment of the two sets of intercalated clutch plates, this friction being determined by a ring 45 which bears against the endmost friction clutch plate port 34 is therefore rotated as long as frictional contact is maintained by the two series of the intercalated plates 48. The rotation of the cylindrical support 35, through the pins 42, effects a rotation of the driving clutch member 4| and since the jaws 42 of this driving clutch member 4| are in engagement with the jaws 5d of the driven clutch member 5B it will be `seen that a drive is effected, through the clutch, to the driven clutch member 58.

,It will further be seen that by the inclination of `the Aslots 43 provided for the pins 42 in the 'driving clutch member 4i, the pressure of the pins 4-2 tends to maintain engagement of the jaws 42 and 55. Thus, las illustrated by dotted lines in Fig. A,tl'iepressure ci the pin l2 in the direcv:tion of Athearrow against the corresponding side i8 and is pressed thereagainst by a plurality of helical compression springs 5t interposed between the ring 49 and an annular collar 5l which is L -shaped in cross section.

One ange of this collar 5l iits in the bore of the cylindrical `extension 33 of the spider 2li and its other ange rits around the cylindrical sleeve 4d ofthe jaw clutch and serves to hold the pins 42 in place. To prevent misalinement of the helical compression springs 55, the ring 4S within each of the springs 55 is preferably formed to provide a stem 52, each of which is slidingly received in a socket 53 formed on the radially extending flange of the annular ring 5l. The position of the ring5| and hence the force exerted by the compression springs 5S is determined by lan end ring 54 which is threaded and screwed into the internally threaded end of the cylindrical extension 30 of the spider 25, the axial position of the ring 5| thereby being determined by the adjustment of the threaded ring 54. The parts of the clutch are preferably protected against the entrance of dust and dirt by a sheet metalicollar 55 which can be secured to the stationary `cylindrical casing in any suitable manner.

The jaws 42 of the jaw clutch 4| are moved axially into engagement with a driven member 5S having mating jaws 5t, such driven members being connected, for example, to the drive shaft of the main motor (not shown) of the airplane, the clutch forming the subject of the invention being adapted to establish a driving connection between the starting motor and the main motor of the airplane.

When the Voperating rod 44 is released, a driving connection is established between the intermeshing teeth' 42 and 59 of the driving clutch member 4| and the driven clutch member 5t, this being established and maintained by thehelical spring .45 which urges `the driving clutch 4| to th'e right, as viewed in Figs. l and 3, and also by the angularity of the slots 43.

When the clutch is so engaged a drive is established from the driven pinion of the starting motor I0 to the gears l5 and I6 mounted on the bushing I8 and thence through the three planetary gears 2| to the spider 20, the other sides of `the planetary gears 2| meshing with the ring gear 25, this ring gear being secured to the motor ,casing I0 by th'e screws 2t. The rotation of the spider 2G effects the rotation of its integral cylindrical extension 3|! in the bore of whichis keyed the alternate series of friction clutch plates 43, the other series of these plates 48 being keyed to the periphery of the cylindrical support 34 which is centered by the stem 32 projecting co-` axially from the spider 2D. This cylindrical supof the angular slot 43 tends to urge the driving clutch member fil axially to the right or further into engagement with' the jaws 59 of the driven clutch member 58. Therefore the angularity of the slots 43 asshownadds to the force of the spring 45y in ,maintaining engagement of the clutch/jaws .42 and 59 `as long as a driving torque exists, that as long as force is being transmitted through the clutch 4l to the driven member.

t will be seen that the maximum torque which can be transmitted -by the clutchv is determined by the frictional engagement of the intercalated clutch plates 43. This friction can be adjusted by turning the threaded ring 54, the adjustment of this threaded ring determinng the axial position of the ring 5|. Since the corresponding ends of the springslitl are seated on this ring 5|, it will be seen that this axial adjustment of the position of this ring 5i `.letermines the pressure which' these springs 55 exert against the ring 49. this ring `49 in turn bearing against the endmost of the intercalated plates 45 and its bearing pressure thereby determining the friction between the two alternate series of intercalated plates 43.

When it is desired to release the clutch, the operator pulls upon the rod 44. This draws the driving clutch member ,4i from the dotted to the full line position shown'in Fig. 3, thereby disengaging its jaws -42 from the jaws 53 of the driven clutch .member 58. This movement is eifected against the resistance of the spring 45. However, the opening of the clutch is usually initiated bythe fact that the main engine (not shown) has been started. When this main motor starts, th'e driven clutch member rotates at a higher rate of speed than the driving jaws 42 of the clutch lI and in the same direction as before, that is, in the direction of the arrow associated with Fig. 4. When :this occurs the slanting advance faces of the jaws 55 engage th'e slanting trailing faces of the jaws 42, the wedging action between these sets of jaws tending to move the clutch 4| to the left, as viewed in Figs. 3 and ll, or to a disengaged position. This automatic disengagement of the jaws 42 and 59 is also facilitated by the angularity of the slots 43. Thus, on reverse torque, that is, from th'e driven. member 53 to the clutch 5| in the direction of the arrow associated with Fig. 4, the upper wall of each slot 43, as viewed in Fig. 4, is caused to bear against the corresponding 'pin 42. The wedging action produced tends to Vmove the clutch 4| to the left, as viewed in Figs. 3 and 4, and to disengage the jaws l2 and 59. ing when usedbetween a starting motor and a main motor, as proposed. However, to avoid clicking of the jaws 42 and 59, lafter the main motor has been started the rod 44 is drawn The, clutch' is therefore self-disengagz agalnstthe resistance of the spring I to effect agcompl'ete disengagement of these jaws 42 and 5 v From the foregoing it willbe seen that the present invention provides 'a very simple and compact clutch mechanism` for :transmitting heavyloads and in'whlch adequate means are provided to permit slippage 'when overloads are encountered and it will further be seen that the engagement'and disengagement of the-jaws of the lclutch are effected smoothly and positively. The Vclutch' is also self disengaging when used as the clutch between an internal combustion starting engine and the main engine of, for exn Iample, an airplane. c

I claim as my invention: y

1v. A clutch for releasably coupling a driving and a driven part, comprising a cylindrical body arranged coaxially of said driving part and rotating therewith, a second cylindrical body iitting the cylindrical surface of said iirs't cylindrical body and having jaws adapted to engage with jaws of said driven part, means for moving said second cylindrical body axially relative to said first cylindrical body to engage and disengag'e said jaws, and means compelling said cylindrical bodies to rotate in unison, comprising a projection secured to one of said cylindrical bodies and extending radially therefrom into a helical slotprovided in the other cylindrical body. 2. A clutch for releasably coupling a drivingr and a driven part, comprising a cylindrical body arranged coaxlally o-f said driving part and rotating therewith, a second'cylindrical body tting the cylindrical surface of said nrst cylindrical body and.' having jaws adapted to engage with jaws of said driven part, means for moving said second cylindrical body axially relative to said first cylindrical body toengage and disengage said jaws, and means compelling said cylindrical bodies to rotate in unison, compris-ing a projection secured toone of -said cylindricalA bodies and extending radially therefrom `into a' helical slot provided in the other cylindrical body, said slot being arranged `at an angle to the axis of said cylindrical bodies to keffect a rotative movemen-t of said second cylindrical bo-dy upon moving it axi-ally relative to said first cylindrical body.

3. A clutch for releasably coupling a driving and a driven part, comprising a cylindrical body arranged coaxially of said driving part and rotating therewith, a second cylindrical body tting the cylindrical surface. of said first cylindrical body and having axially Vextending face jaws adapted to engage with axially extendinglface jaws of said driven part, means for moving said second cylindrical body axially relative to said rst -cylindrical body to engage and disengage said jaws, and means compelling said cylindrical bodies to rotate in unison, comprising a projection secured to fone of said cylindrical bodies and extending radially therefrom into a helical slot provided in the other cylindrical body.

4. A clutch for releasably coupling a driving part and a driven part, comprising a cylindrical body arranged coaxially of said rdriving part and rotating therewith, a second cylindrical body f1tting the cylindrical surface of said first cylindrical body and having face jaws extending axially therefrom and having abrupt driving faces and inclined trailing faces and adapted to engage counterpart face jaws provided on said driven part, means for moving said second cylindrical body axially relative to said first cylindrical body to engage and disengage said jaws, and means compelling said cylindrical bodies to rotate in unison, comprising a projection secured to one of said cylindrical bodiesy and extending radially therefromvin-to a helicalv slot provided in the other cylindrical body, the line of slope of said slot being generally perpendicular to the trailing faces of the adjacent jaws o-f said second cylindrical body.

'5. A clutch for releasably coupling a driving and a driven part, comprising a cylindrical body arranged coaxially of said driving part and rotating therewith, a -second cylindrical body in thek form of a sleeve tting the exterior cylindrical surface of said first cylindrical body and having face jaws extending axially therefrom and adaptedto engage counterpart face jaws of said driven part, means for moving said second cylindrical body axially relative to said first cylindrical body to engage and disengage said j-aws, and means compelling said cylindrical bodies to rotate in unison, comprising a pin secured to said first cylindrical body and extending radially outward therefrom'into a helical slot provided vlin the' second cylindrical body, said slot being so Iarranged helically to effect a rotative movement of said second cylindrical body upon moving it axially relative to said first -cylindrical body.

6. A clutch for releas-ably coupling a driving and a driven part, comprisinga cylindrical body arranged coaxially of said driving part and rotating therewith, a second cylindrical body fitting the cylindrical surface o-f said irst cylindricalfbody and having jaws adapted to engage Iwithjaws of said driven part, .a spring interposed rotating therewith, a second cylindrical body fitting the cylindrical surface of said iirst cylindrical body and having jaws adapted to engage with jaws of said driven part, a spring interposed between said cylindrical bodies and urging them A`axially apart to engage said jaws, means for moving said second cylindrical body in the oppopsite direction to disengage said jaws, and means compelling said cylindrical bodies to rotate in unison, comprising a projection secured to one of said cylindrical bodies and extending radially therefrom into a helical slot provided in the other cylindrical body.

8. A clutch for relea-sably coupling a driving and a driven part, comprising a cylindrical body arranged coaxially of said driving part and rotating therewith, a second cylindrical body ntting the cylindrical surface of said first cylindrical body and having jaws adapted to engage with jaws of said driven part, a spring interposed between said cylindrical bodies and urging them axially apart t0 engage said jaws, means for moving said second cylindrical body in the opposite direction to disengage said jaws, and means compelling said cylindrical bodies to rotate in unison, comprising a projection secured to one ,of said cylindrical bodies and extending radially therefrom into a helical slot -provided in the other cylindrical body, said slot being arranged at an angle to the axis :of saidvcyli-ndrical bodies to effect a Arotative movement of said sec-` ond cylindrical body upon moving it axially rela*- tive Yto said rst cylindrical body.

9. A clutch `for relea'sably coupling a driving and a driven part, comprising a cylindrical body arranged coaxially of said driving part and rotating therewith, a second cylindrical body fitting the cylindrical surface of said rst cylindrical body and having jaws adapted to engage with jaws of said driven part, a spring interposed between said cylindrical bodies and urging said second `cylindrical body axially in one direction, a rod secured to the axis of said second cylindrical body .and extending through a bore provided in said first cylindrical body for moving said second cylindrical body axially inthe opposite direction, said jaws being engaged and disengaged by said axial movements of said second cylindrical body, and means adapted to operatively connect said cylindrical bodies, comprising a projection secured to one of said cylindrical bodies and extending radiallyr therefrom into a slot provided in the other cylindrical body.

l0. A clutch for releasably coupling a driving and a driven part, comprising a stationary ring gear, a pinion driven by said driving part, a rotatable spider carrying pinions meshing with said stationary ring gear and pinion, a coaxial cylindrical member carried by said spider, a cylindricalclutch member slidingly mounted on said nrst cylindrical member and having face jaws at one end adapted to engage similar jaws on said driven part, a pin connecting said cylindrical members and arranged in a slot provided in one to compel said cylindrical members to turn in unison but permitting relan tive axial movement therebetween, and means for manually moving said cylindrical members axially to engage and disengage said face jaws.

il. A clutch for releasably coupling` a `driving and a driven part, comprising `a stationary ring gear, a pinion driven by said driving part, a rotatable spider carrying pinions'meshing with said stationary ring gear and pinion, a coaxial cylindrical member carried by said spider, a cylindrical clutch member slidingly mounted on said first cylindrical member and having face jaws at one end adapted to engage similar jaws on said driven part, a pin connecting said cylindrical members and arranged in a slot provided in one to compel said cylindrical members to turn in unison but permitting relative axial movement therebetween, said slot being arranged at an angle to the axis or said cylindrical members to clutch effect a lrot-ative movement of said cylindrical clutch member upon moving it axially relative to said first cylindrical member, and means for moving said cylindrical clutch member axially to g engage and disengage said `face jaws.

12. A clutch for releasably coupling a driving and a driven part, comprising a stationary ring gear, a pinion driven by said driving part, .a rotatable spider carrying pinions meshing with said stationary ring gear and pinion, :a coaxial cylindrical member carried by said spider, a cylindrical clutch member `slidinglymounted on said rst cylindrical member and having face jaws at one end adapted to engage similar jaws, :on said driven part, a pin cennecting said cylindrical members and arranged in a slot provided in one to compel said cylindrical members to turn in unison but permitting relative axial movement therebetween, means for moving said cylindrical clutch member axially to engage and disengage said face jaws, and a friction clutch interposed between said cylindrical members.

13. A clutch for releasably coupling a driving and a driven par-t, comprising a stationary ring gear, a pinion driven by said driving part, a rotatable spider carrying pinions meshing with said stationary ring gear and pinion, :a coaxial cylindrical member carried by said spider, a cylindrical clutch member slidingly mounted on said first cylindrical member and having face jaws at one end adapted to engage similar jaws on said driven part, a pin connecting said cylindrical members and arranged in a slot provided in one to ycompel said cylindrical members to turn in unison but permitting relative axial movement therebetween, and means for manually moving said cylindrical clutch member axially to engage and disengage said face jaws, comprising a coaxial rod connected to said cylindrical clutch member and extending through bores provided in said first cylindrical member and spider, and means adjacent said s, ider for manually moving said rod axially.

CHARLES A. BALTON.

REFERENCES CITED The following references are of record in the iile oi this patent:

UNITED STATES PATENTS Number Name Date 1,876,642 Doub Sept. 13, 1932 1,955,110 Brockway Apr. 17, 1934 1017,46@ Lansing Oct. 15, 1935 2,075,119 Lansing Mar. 30, 1937 2,338,403 Callsen Jan. 4, 1944 

